September weather forecastWilliamstown, VT
September
Weather in September
The first month of the autumn, September, is still a refreshing month in Williamstown, Vermont, with an average temperature fluctuating between 48°F (8.9°C) and 67.6°F (19.8°C).Temperature
The arrival of September signals a subtle shift in temperature, down from a moderately hot 74.8°F (23.8°C) in August to a refreshing 67.6°F (19.8°C). An average temperature of 48°F (8.9°C) is recorded during the nights in September.Humidity
In September, the average relative humidity is 81%.Rainfall
September is the month with the least rainfall. Rain falls for 13.1 days and accumulates 2.09" (53mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 30min.On the first day of September, sunrise is at 6:14 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:32 pm EDT.
Sunshine
The average sunshine in September is 8h.UV index
The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, a daily maximum UV index of 3 leads to the following instructions:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Williamstown, VT
- Average high temperature in September: 67.6°F
The warmest month (with the highest average high temperature) is July (76.8°F).
The month with the lowest average high temperature is January (23.2°F).
- Average low temperature in September: 48°F
The month with the highest average low temperature is July (55.2°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).
Average pressure in September
Williamstown, VT
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Williamstown, VT
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is April (7.3mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in September
Williamstown, VT
- Average humidity in September: 81%
The months with the highest relative humidity are January and February (89%).
The month with the lowest relative humidity is May (76%).
Average rainfall in September
Williamstown, VT
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is June (3.43").
The driest month (with the least rainfall) is September (2.09").
Average rainfall days in September
Williamstown, VT
- Average rainfall days in September: 13.1 days
The month with the highest number of rainy days is June (18.8 days).
The month with the least rainy days is January (6.8 days).
Average snowfall in September
Williamstown, VT
- Average snowfall in September: 0"
The month with the highest snowfall is February (13.31").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Williamstown, VT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (22.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Williamstown, VT
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 8h and 0min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The months with the least sunshine are January and February (Average sunshine: 2h and 42min).
Average sunshine days in September
Williamstown, VT
- Average sunshine days in September: 14.6 days
The month with the most sunshine days is September (14.6 days).
The month with the least sunshine days is February (5.5 days).
Average UV index in September
Williamstown, VT
- Average UV index in September: 3
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in September
Williamstown, VT
- Average cloud cover in September: 43
The months with the most cloud cover are January and February (Cloud cover 74).
The month with the least cloud cover is July (Cloud cover 39).
Average visibility in September
Williamstown, VT
- Average visibility in September: 5mi
The months with the highest visibility are April, May, June, July, August, September, October and November (5mi).
The months with the lowest visibility are January, February, March and December (4mi).
